Engine.



B. v. NORDBERG.

ENGINE. APPLICATID N FILED JAN. 28, 1914.

v 1 jwvenffi 0 7". W 4

nisrir i sens BRUNO V. NORDBERG, 0 MILWAUKEE, WISCONSIN.

ENGINE.

women.

Specification of Letters'Fat'ent.

Patented Get. it}, itfitfi.

Application filed January 28, 1914. Serial Ho. 814,883.

' r are usually provided with condeilsei's.

The inaii'i"'iibiie( :t "5i tliei ve tion is to provide for eliminatingor reducing coiiipression on the return strokes of the piston in anengine of this type, in order that it may be maneuvered or its operationcontrolled with precision.

it consists in the provision otma central exhaust port engine withauxiliary exhaust valves and with means for bringing such valves intooperation so as to eliminate or reduce compression when the engine isrun slowly and it is desired to control its operation with precision,and it consists further in the peculiar construction, arrangement andcombination of parts as hereinafter particularly described and pointedout in the claims.

In the accompanying drawing like charactcrs designate the same parts inthe several figures.

Figure 1 is a view partly in side elevation and partly in vertical axialsection of a pm tion otan engine embodying the invention; and Figs. 2and 3 are diagrams illustrating the operation of the engine.

in engines of the mid-cylinder or central exhaust type there areordinarily no exhaust valves, but the piston. which is of somewhatlesslength than the length of the cylinder and the. stroke of the piston isadapted to uncover the central-exhaust port and thereby alternately openthe opposite ends of the cylinder to exhaust-as the piston approachesthe ends of its stroke and its movement is reversed. The exhaust port ison ied for a comparatively short time, from out' onetenth to'aboiitbnesixth of the per 0d of one revolution of the crank shaft. 0n thereturn'strokes of the piston the steam confined in the cylinder iscompressed. Fig. 3 shoi ing an indicator (llilglml'islllllSllIililGS thedistribution of the steam orworking fluid in the cylinder of an engineof this kind when running under normal conditions. In this passage 2.

diagram a represents the admission period, and b the expansion period.At the point 0 the piston begins to uncover the exhaust port. At (Z thepiston reaches the end of its working stroke, and on its return strokeat the point e, closes the exhaust port, so that during the period whilethe piston is traveling the distance on its forward or working strokeand back the same distance on its .return stroke, the exhaust port isopened. The path described by the crank pin of the engine is partiallyindicated on this diagram by the dotted line 9, and the period duringwhich the exhaust valve is open, by the angle Ii. On the return strokeof the piston from the point c to its end, the steam or working fluid iscompressed as indicated by the curved line c Z.' In an engine'of thiskind, however, the supply of the steam or Working fluid to the cylinderis controlled and regulated, the compression is substantially constant,and progresses according to the line ci. If such an engine is used forhoisting or similar purposes where it is necessary to maneuver orcontrol its operation with precision so that it can be run backward orforward at very low speed, and where it is necessary to stop withaccuracy at certain points in the. stroke of the piston, the comenginewith precision and also difiicult to start it.

Referring to Fig. 1 of the drawing, 1 designates an engine cylindersurrounded at the center by a belt or passage Qand having acircumferential series of openings 3 communicating with said passage andforming the main mid-cylinder or central exhaust port. to the cylinderand communicates with the At its ends the cylinder is provided withinlet ports 5 and auxiliary exhaust ports 6. These are preferably formedas shown, in the cylinder heads. The inlet ports are controlled byrotative or other suitable valves 7 one of which is shown at the right,and these valves may be operated under the control of. the governor, byCorliss or other suitable valye gear, as shown at the left, Fig. l.

As engines of this type usuallyhave a long preferably consists of twoheads 8, separated by an insulating space with which the mid.

The main exhaust pipe 4 is attached l exhaust port 3 connnunicates oneach stroke of the piston and in which a vacuum or par- .tial vacuum isthus produced andmaintained while the engine is in operation. Thisconstru'ction not only reduces theweight ot the piston, but alsoobstructs the passage of heat through it from one end of the cylinder tothe'other, However, for engines of comparatively short stroke the pistonmay be made with a solid or single head.

mechanism are the same at both ends oi the cylinder, that at one-endonly will be specifi cally described..- This mechanism comprises arocker arm 12, which is fixed on the valve stem and is provided with atrip steel or block, a rocking valve actuating. lever 13, ;which i'sfulcrumed on the valve bonnet concentrically ,with the valve stem, and atrip hook 14, whiohis pivoted to the lever 13 and provided With a tripsteel orblock adapted to coiiperate with the trip steel or block ontheiarm 12 to open the associated valve-9.v

The lever 13 is conneetedby a rod 15 with the wrist plate "12. A spring16 or other suitable device, tends to hold the trip hook 14: in positionto cooperate with the arm 12, for opening the valve 9. The hook 1 1. hasan. arm 17, provided with a roller 18 for turning andholding the hookout of operative position for opening the valve. The arm 17 is of such.length and is of such angu' lar relation to the hook' that when the hookis in operative position for opening the valve, the roller 18 will be inaxial alinement with the valve stem, as shown.

A knock-off or releasing cam or lever 19,

fulcrumed on the valve bonnet or otherpart of the engine, is adapted inone position, as shown by full lines, Fig. l, to release the triphook-l4: and permit it to'open the valve 9,

and in another position, indicated by a dotted line, to throw and holdsaid hook out of operative position for opening the valve. The bent orlever 19 isconnected by a system of levers and rods 20, 21., 22, 23, 24,25,

I 26 and 2-7 with the counterpoise 28 of a centrlfugal governor 29, sothat when the engine runs slowly and the couuterpoise is down, theknock-off or releasing lever will be held in the position in which it isshown by full lines, and the auxiliary exhaust valve will be openedduring the latter part of the return stroke of the. piston, and closedduring the workingstroke of the piston, but when the. engine runs atnormal or high 55 speed, and the counter-poise of'the governor gage withthe arm 12 and close the valve 9,' when the lever 13 is moved by thewrist plate in the direction indicated by an ar row, Fig. 1. The valve 9is arrested and held in closed position by a stop 31 with which the arm12 engages when the valve is closed by the shoulder 30 on the hook 14.

The lever 25 is'weighted, so that when the engine is run slowly and thecounterpoise 28' of the governor is down, the cam or lever 1.9 will'beheld in releasing position, as shown by full lines on the drawing,thereby causing the auxiliary exhaust valves 9 to open .and close asherelnbefore explained; Under" these conditions the distribution ofsteam or other working fluid in the engine cylinder will take place asillustrated by the indicator card or. diagram shown. in Fig. 2. Ac-

cording to this diagram the admission of steam or other working fluidtakes place from j to 7c. From 1c to Z 1t expands, and at Z the centralexhaust portis opened and remains open during the period represented bythe curved line r-m. In the meantime, the auxiliary exhaust valve 9 isopened, thereby preventing compression of the steam or working fluid onthe return stroke of the piston, so that the exhaust line m.n issubstantially straight. closes, thereby, producing a slight compression,indicated by the curve at the lower end" of the line j n. If desired,the auxiliary exhaust valves may be closedexactly on dead centers, thuscompletely eliminating cornpression. With a distribution of the steam orworking fluid, as illustrated by this-card or diagram, theengine can beeasily maneuvered, and its operation controlled with precision.

When the speed of the engine is increasedsufficiently to lift thecounterpoise 28 of the governor, and while it continues to run at highor normal speed, the cam or lever 19 will be shifted by its connectionwith the governor and held in position, as indicated by dotted lines, toprevent the opening of the auxiliary exhaust valves 9', which willremain closed and inactive until-the speed of the engine is reducedsufiiciently to permit the counterpoise 28 of the governor to drop,- asshown by full lines on the drawing. \Vhen the engine runs at high ornormal speed, distribution of the steam or working fluid will take placein the cylinder, as illustrated by the indicator card ordiagram, Fig. 3,and as hereinbefore explained. I

At a the exhaust valve For manually shifting the kIlOCk-Ofi or releasing cam or lever 19 independently of the governor, a handv lever 32is connected by a rod 33 with the Weighted lever 25, the rods 26 and 33having slot and pin connections with the' lever 25 to permit turningsaid lever into releasing position by either connection independently ofthe other.

Various changes in the construction, arrangement and combination ofparts may be made Without departure from the principle and scope of theinvention as defined in the following claims.

I I claim: y

1. In an engine the combination with a cylinder having a central exhaustport and a piston adapted atthe limits of its movement in oppositedirections to open said port, of auxiliary exhaust valves, means foroperating said valves, and a governor connected with said valveoperating means and adapted when the engine runs below a certain speedto-cause the opening'of said valves during the latter part of the returnstrokes of the piston.

2. In an engine the combination with a cylinder having a central exhaustport and auxiliary exhaust ports at the ends and a piston adaptedadjacent to the limits of its movement in opposite directions to uncoversaid central port, of valves controlling said auxiliary exhaust ports,valve operating mechanism comprising rocker arms connected with saidvalves, rocking levers, trip hooks pivoted to said levers and adapted toengage with said arms to open said valves on the latter part of thereturn strokes of the piston, releasing levers adapted to hold saidhooks out of operative position, and means for turning said releasinglevers into position to render said valves active or inactive.

3. in an engine the combination with a cylinder having a central exhaustport and a reciprocating piston adapted at the limits" of its movementin. opposite directions to open said port, of auxiliary rotative exhaustvalves, valve gear for opening and closing said valves comprising armsfixed 'oii the, valve stems, valve operating levers fulcriimedconcentrically with the valve stems, trip hooks pivoted to said leversand adapted to engage with said arms and to open the valves on thelatter part of the return strokes of the piston, knock-off leversadapted to turn said trip hooks out of operative position, and agovernor conncctcdavitli said knock-oil levers and adapted when theonnine attains a certain speed to shift them into releasing position.

in an engine the combination with a cylinder having a centralexhaustpoi-laud auxiliary exhaust ports at the ends, and a pistonadapted to uncover said central port adjacent to the limits of themovement of the piston in opposite directions, of valves controllingsaid auxiliary exhaust ports, valve operating mechanism co'm prisin grocker arms connected with said valves, rocking lovers, trip hookspivoted to said levers and adapted by engagement with said arms to opensaid valves during the latter part of the return strokes of the piston,releasing levers adapted to hold said hooks out of operative position,and means for shifting said releasing levers into position to rendersaid valves active or inactive, said hooks being provided with shouldersadapted by engagement with said arms to close said valves just beforethe beginning of the working strokes of the piston in whichever positionthe releasinglcvers may be. V

in an engine the combination with a cylinder having a central mainexhaust port, auxiliary exhaust ports at the ends, and a reciprocatingpiston adapted at the limits of its movement in opposite directions touncover the central exhaust port, of auxiliary rotativc exhaust valvescontrolling the auxil-- iary exhaust ports, valve gear for opening 9 andclosing said valves comprising arms fixed on the valve stems, valveoperating levers lulcrumcd concentrically with the valve stems, triphooks pivoted to said levers and adapted by engagement with said arms toopen said val'vcs during the latter part of the return strokes of thepiston, knock-off levers adapted to turn said hooks out of operativeposition, and a governor connected with said knock-oil levers andadapted to 00 shift them into releasing position when the engine attainsa certain speed, said hooks being provided with shoulders which areadapted to close said valves just before the beginning of the workingstrokes of the piston, when the knock-fill levers are in eitherposition.

(3. 111 an engine the combination with a cylinder having a centralexhaust port and auxiliary exhaust ports at the ends and a pistonadap'lcd at the limits of its'movciiieiit in opposite directions touncover said central port, of valvcs controlling said auxiliary ports,valve operating nicchai' isin comprising rocker arms connected with saidvalves, 115 rocking levers whose fulcrunis are in axial alinciiicut withthe pivots of said arms, trip for opening the valves, and means forturniliar i exhaust ports at the ends and a reciprocating pistonadapted. at the limits of its movement in. opposite directions touncover the central exhaust port of auxiliary rotative exhaust valvescontrollingthe auxiliary exhaust ports, valve gear for opening andclosing said valves comprising arms iixed on the valve stems, valveoperating le\'ers,;tulcrumed concentrically with the valve stems, triphooks pivoted to said levers and adapted by engagement with said arms toopen said elves during the latter part of the return strokes ofthepiston, springs tending to hold said hooks in operative position, triparms connected "with said hooks and provided With rollers in axial.alinement with the valve stemsv when the hooks are in engaginr position,knocloofl levers adapted by engagement With said rollers to turn andhold said 'hooks out of operative position, and a governor connectedwith said knockofl" levers and adapted when the engine at;

tains a certain speed to shift them into re leasing position.

8. In an engine the combination of a cylinder havinga central exhaustport and aux- I iliary exhaust ports at the ends and a piston adapted atthe'liinits of its movement to adapted by engagement with said arms. to

- open the valves during the latter part of the return strokes of thepiston,'said hooks having shoulders adapted to close the valves justbefore the beginning of the Working strokes of the piston, stops forarresting; and

the valve stems, valve operating levers fulcrumed concentrically withthe valve stems, trip hooks pivoted to said levers and adapt ed byengagement With said arms to open said valves during the latter part-oithe re- "holding said arms with the valves in closed.

turn strokes of the piston, said hoohs being; provided with shoulderswhich are adapted to close said valves just before the beginning of theWorking strokes of'the piston, stops for arresting and holding saidvalves in closedposition, knock otl "levers adapted to turn said hooksout of operat and a governor, connected With said in. off levers andadapted when the engine at position A tains a certain speed to-shift thea. into re 5 leasing position.

1.0. In an engine the combination of a indcr having a central exhaustport and a iliary exhaust ports at the ends and. a pis ton adapted atthe limits movement to open said central port to (apposite .iHlZlC-llthe cylimler alternately, of valves control lin 'said auxiliary exhaustports, valve crating and releasin niechanr open said valves during thepair the return strokes of the piston and to close them during theWorking strokes'o' the piston. a. weighted lever connected wit sa valveoperating and releasing mechanism and tending tohold the same inreleasing an weighted lever into position to cause saidv mechanism toopen said. valves.

ll. In an. engine the combination. Wi cylii'ider having a centralexhaust port, auxas iliary exhaust ports at the ends a piston adapted atthe limits of its movement in opposite directions to uncover the centralexhaust port, of auxiliary exhaust valves controlling the auxiliaryexhaust ports,

valve operating and releasing gear adapted to open theauxiliary exhaustvalves during the latter part of 'the return strokes of the piston andto close said valves during the rm-kiln; strokes of the pit. leverconnected with the valve operating and releasing gear and tending. toprevent the opening of said exhaust valves, and a governor connectedwith said weighted lever and adapted when the engine attains a cer- 110.tain speed to shift said weighted lever to cause the valve gear to openthe exhaust valves during the latter part 01: the return strokes of thepiston.

12. In an engine the combination of a cyllnder having central exhaustport and auxiliary exhaust ports at the ends and a piston adapted at thelimits o'f i'ts movement to alternately open said central port tooppositeends'of "the cylinder, of valves controlling'said auxiliaryports, valveoporating mechanism comprising rocker arms connected withsaid valves, rocking levers, hooks pivoted to said levers and adapted byengagement with said arms to" open the valves during the latterpart ofthe return strokes of the piston, trip arms connected with said hooksand provided with. rollers wh ch are in axial alinement with the ful-rcrums of said levers when the hooks are in l Weighted 105 engagingposition, releasing levers adapted by engagement with said rollers toturnand hold said hooks out of engaging position, and means for manuallyshifting said re- 5 leasing levers into position to prevent opening saidvalves.

1-3. In an engine the combination with a cylinder having a centralexhaust port, auxiliary exhaust ports at the ends and a piston 10adapted at the limits of its stroke to uncover the central port. ofvalves controlling said auxiliary exhaust ports, means for operatingsaid valves. a governor connected with said valve operating means andadapted 15 when the engine attains a certain speed to automaticallyarrest the operation of said valves and when the engine runs below' thatspeed to automatically cause the opening of said valves during thelatter part of the re- 7 turn strokes of the piston, and a connectionfor manually releasing the valve operating gear to permit the valves toremain closed independently of the governor.

' In witness \vhereofI hereto afiix my signature in presence of twowitnesses.

BRUNO v. NORDBERG.

\Vitnesses CHAS. L. Goss, E. C. BAYERLEIN.

